Add support for enums within structs and interfaces to mojom.

mojo/public/bindings/sample/sample_service_unittests.js

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 define([
     "console",
     "mojo/apps/js/test/hexdump",
     "gin/test/expect",
     "mojom/sample_service"
   ], function(console, hexdump, expect, sample) {
@@ skipping 74 matching lines @@
     expect(foo.source).toBe(0xFFFF);
   }
 
   function ServiceImpl() {
   }
 
   ServiceImpl.prototype = Object.create(sample.ServiceStub.prototype);
 
   ServiceImpl.prototype.frobinate = function(foo, baz, port) {
     checkFoo(foo);
-    expect(baz).toBeTruthy();
+    expect(baz).toBe(sample.ServiceStub.BazOptions.BAZ_EXTRA);
     expect(port).toBe(10);
     global.result = "PASS";
   };
 
   function SimpleMessageReceiver() {
   }
 
   SimpleMessageReceiver.prototype.accept = function(message) {
     if (dumpMessageAsHex)
       console.log(hexdump.dumpArray(message.memory));
     // Imagine some IPC happened here.
     var serviceImpl = new ServiceImpl();
     serviceImpl.accept(message);
   };
 
   var receiver = new SimpleMessageReceiver();
   var serviceProxy = new sample.ServiceProxy(receiver);
 
   var foo = makeFoo();
   checkFoo(foo);
 
   var port = 10;
-  serviceProxy.frobinate(foo, true, port);
+  serviceProxy.frobinate(foo, sample.ServiceProxy.BazOptions.BAZ_EXTRA, port);
 });